Problem: Simplify the following expression: $k = \dfrac{6}{7p} + \dfrac{8}{3p}$
In order to add expressions, they must have a common denominator. The smallest common denominator is the least common multiple of $7p$ and $3p$ $\lcm(7p, 3p) = 21p$ $ k = \dfrac{3}{3} \cdot \dfrac{6}{7p} + \dfrac{7}{7} \cdot \dfrac{8}{3p} $ $k = \dfrac{18}{21p} + \dfrac{56}{21p}$ $k = \dfrac{18 +56}{21p}$ $k = \dfrac{74}{21p}$